Lay out instrument



Aug. 30, 1960 G. c. BURGEss LAY OUT INSTRUMENT 3 Sheets-Sheet 1 FiledFeb. 25, 1957 Aug. 30, 1960 s. c. BuRcsEss LAY OUT INSTRUMENT 5Sheets-Sheet 2 Filed Feb. 25, 1957 Aug. 30, 1960 G. c. BuRGEss LAY ouTINSTRUMENT 3 Sheets-Sheet 5 Filed Feb. 25, 1957 ma 0E Tav Nr .s nu 9 9m+n f cmo e au,+ .A e f v Y B .lllllllll/ Patented Aug. 30, 1960 freeLAY OUT INSTRUMENT 'George C. Burgess, 211A 4th Ave., Columbia, Tenn.

Filed Feb. 25, 1957, Ser. No. 642,097

11 Claims. (Cl. 33-26) This invention relates to a layout instrument andmore particularly -to an instrument which shall be adapted for layingout annular or curved members, such as marking the bolt hole positionsin annular flanges and the like.

An object of my invention is to provide a layout instrument of thecharacter designated in which a plurality of angularly spaced markingsmay be accurately applied to the member to be laid out in a of time.

Another object of my invention is to provide a layout instrument of thecharacter designated which shall include magnetic means holding theinstrument in predetermined alignment with a supporting surfaceregardless of the position of the supporting surface whereby theinstrument may be readily applied to the supporting or working surface.

Another object of my invention is to provide a layout instrument of thecharacter designated which Shall be adapted for applying both circularand transverse marks at specific angular positions on the member beinglaid out.

A further object of my invention is to provide a layout instrument ofthe character designated which shall include improved means foradjusting and setting the radius of the circular marking member andshall include hnproved means for setting the selected angular positionsto be marke`d by the transverse marking member.

A more speciiic object of my invention -is to provide releasable meanswhich permits the transverse marking member to be moved sequentially tothe selected angular i positions on the member being laid out.

A still further object of my invention is -to provide a layoutinstrument of the character designated which shall he simple ofconstruction, economical of manufacture and one which is positive inoperation.

Briefly, my improved layout instrument comprises a supporting basehaving a magnet associated therewith for holding the base inpredetermined `alignment with a supporting surface. Annular membershaving a plurality of angularly spaced recesses therein are mounted onthe base. Mounted for rotary movement adjacent the center of the annularmembers is a bracket which carries an elongated member which isadjustable relative to the bracket. Rotatable with the elongated memberand adapted to engage the recesses in the annular member is a latchmember for holding the elongated member in selected angular positions. Apair of marking members are mounted adjacent the outer end of theelongated member, one marking member being mounted for pivotal movementwhereby a mark is made transversely of a circular mark made by the othermarking member.

Apparatus embodying features of my invention is illustrated in theaccompanying drawings forming a part of this application, in which:

Fig. l is a side elevational view, partly broken away and in section;

Fig. 2 is a plan view, partly broken away, with the upper retainingcollar of one of the marking members being omitted for the sake ofclarity;

Fig. 3 is a sectional view taken generally along the line lll-III ofFig. 2;

Fig. 4 is a sectional view taken generally along the line IV--IV of Fig.l;

Fig. 5 is a fragmental plan view of the apparatus shown in Fig. 4;

Fig. 6 is a fragmental side elevational view showing the opposite sideof the bracket and elongated member from that shown in Fig. 1; and,

Fig. 7 is an end elevational view, partly broken away.

Referring now to the drawings for a better understanding of myinvention, l show an annular base member 1G having an upper wall 11formed integrally therewith, as shown in Fig. 1. A centrally disposedopening 12 is provided in the upper wall 11 for receiving a cup shapedmember 13. Secured to the cup shaped member 13 above and below the wall1-1 are collars 14 and 16 which limit axial movement of the cup shapedmember relative to the wall 11. Secured to the undersurface of the cupshaped member 13 is a circular plate 17 which carries a beveled ringgear 18 at the periphery thereof. A suitable opening 19 is provided inthe base 10 for receiving a shaft 21 having a beveled gear 22 at theinner end thereof which meshes with the beveled ring gear 18. A collar23 is attached to the shaft 21 by means of a set screw 24 to limit axialmovement of the shaft 21 relative to the base 10. A suitable operatingknob 26 is secured to the outer end of the shaft 21 for rotating thesame.

Mounted Within the cup shaped member 13 are upper and lower bearings 27and 28, respectively, for receiving the lower end of a vertical shaft29. The outer races of the bearings 27 and 2S engage the inner surfaceof the cup-shaped member 13 with a press lit whereby the bearings areheld against axial movement relative to the cup shaped member. The innerraces of the bearings 27 and 2S engage the shaft 29 with a press fitwhereby the shaft is held against axial movement relative to the innerraces of the bearings.

Secured rigidly to the cup shaped member 13 above the collar 14 is acircular plate 31 having a raised central portion 32. A As shown in Fig.1, the upper end of the cup shaped member 13 flares outwardly to form anannular outturned flange 33. Surrounding the shaft 29 and secured to theoutturned flange 33 of the cup shaped member 13 by means of a screw 34is a disc like collar 36.

Mounted on lthe plate 31 outwardly of the raised portion 32 thereof areconcentric rings or annular members 37, 38, 39, 41 and 42 which aresecured to the plate 31 by any suitable means, such as screws 43, 44,46, 47 and 43 which pass through suitable openings in the plate 31 andthen into threaded openings in the annular members. The annular member37 is provided with angularly spaced recesses 49 therein which arespaced approximately 45 from each other. The annular member 38 isprovided with recesses 51 therein which are angularly spaced 15 apart.The -annular member 39 is provided with recesses 52 therein which areangularly spaced 30 apart. The annular members 41 and 42 are providedwith angularly spaced recesses 53 and 54, respectively, which are spaced2 apart. As shown in Fig. 2, the recesses 53 are spaced midway betweenthe recesses 54 whereby each recess 53 is positioned V1 from each of theadjacent recesses 54. The recesses 52 are positioned midway between therecesses 51 whereby each recess 51 lies substantially 71/2 -from theadjacent recess 52. The recesses 49 are positioned 71/2" from theadjacent recesses 51, as shown in Fig. 2.

As shown in Fig. 3, mounted on the base 10 by means 3 of screws 56 is-an outstanding bracket 57 having spaced lugs 58 and 59.

Mounted for pivotal movement between the lugs 58 and 59 on atransverseshat 61 is a lever arm 62 having an inwardly extending detent63 positioned opposite the annular member 42. Angularly spaced recesses64, 65, 66 and 67 are provided in the annular member 42Vfor receivingVthe detentrr63, as shown in Fig. 2. The recess 64 is positioned 71/2from the recess 65. The recess 65 is positioned from the recess 66 andthe recess 66 is positioned 71/2 from the recess 67. The lever arm 62 isprovided with a depending handle member 70 for removing the detent 63from the recesses in the annular member 42. The detent 63 is urged intoengagement with the recesses by a compression spring 68 which isinterposed betweenthe operating arm 70 and the base 10, as shown in Fig.3. It will thus be seen that by releasing the detent 63 from engagementwith the recesses in the annular member 42, the entire group of annularmembers carried by the plate member 31 may be moved angularly of thebase member to the selected positions as determined by the positions ofthe recesses 64, 65, 66 and 67.

Secured to the upper end of the shaft 29 is a plate 69. Mounted on theplate 69 by means of screws 71 is an upstanding bracket 72 which ispreferably rectangular in shape. A transverse slot 73 is providedadjacent the lower end of the bracket 72, as shown in Fig. l forreceiving a transverse arm 74. Positioned Within the slot 73 and securedto the inner end of the arm 74 is a threaded member 78 for receiving aninternally threaded operating member 79'. As shown in Fig. l, theoperating member 79 is provided with an axially extending portion 81having an annularY recess 82 therein which ts in a suitable openingprovided in a plate-like member 83. The plate-like member 83 is securedto the bracket 72 by means of screws 84. The plate-like member 83engages the shoulders at opposite sides of the recess 82 to limit axialmovement of the operating member 79 relative to the bracket 72. lt willthus be yseen that upon rotation of the operating member 79, thethreaded member 78 together with the arm 74 move transversely of thebracket 72. To lock the arm 74 in selected positions, a threaded opening75 is ,provided in the bracket 72 for receiving a thumb screw 80 whichis adapted to engage the side of the arm 74. Y

MountedV adjacent the outer end of the arm 74 is a Y cylindrical housing86 having an annular inturned ilange 87 formed integrally with the lowerend thereof. Mounted for vertical movement .in the cylindrical housing86 is an actuating rod or latch 88 having a reduced diameter lower end89 for engaging the recesses in the annular members, as shown in Fig. 4.The lower end of the latch 88 is provided with a relatively sharp point91 which is adapted to engage the smaller recesses 53 and 54 formed inthe annular members 41 `and v42, while the larger portion 89 engages therecesses 49, 51 and 52. Surrounding the actuating rod or latch 88 at theupper end of the cylindrical housing 86 is an annular spring abutment 92which is secured to the cylindrical housing, by any suitable means.-Secured to the actuating rod or latch 88 within thehousing 86 is aspring abutment 93. Positioned between thespring abutments 92 and 93 isa compression spring 94 which urges the latch 88 downwardly intoengagement with the recess in the subjacent annular member. Mounted onthe side ofthe cylindrical housing 86 by means of `screws 96 is anupstanding bracket 97. Pivotally'connectedto the bracket 97 by means ofa transverseV pin 98 is a lever arm 99. As shown in Fig. 4, theleverrarm'r99 -is provided with a small diameter portion 101 -which -isadaptedtoslidably engage a -transverse openi11g7102 proyidedgin theupperend of the actuating rod or latch;88. The other-end .of the lever99is provided with an `actuating l'handle member 103 for moving the leverarmabout its pivot pin 98. To lock .the latch 88 in its uppermostposition, I pivotally mount a locking arm 104 on the housing 86 bylmeans of a pivot pin 106, as shown 4 in Fig. 5. The locking arm 104 isrelatively flat and is adapted to engage a transverse notch 107 providedadjacent the upper end of the actuating rod or latch 88. It will thus beseen that by raising the latch 88 so that the transverse notch 107 isopposite the locking arm 104, the latch 88 can be locked in thisposition by moving the arm 104 into engagement with the notch 107.

A transverse slot 108 is provided in the bracket '72 above the slot 73Yfor slidably receiving an arm or elongated member 109. The elongatedmember 109 is held in the transverse slot 108 by means of a plate 111which is secured in place by screws 112.

Extending longitudinally of one side of the elongated member 109 andsecured thereto by any suitable means is a rack 113. A verticallyextending opening 114 is provided in the bracket 72V for receiving avertical shaft 116 having a pinion 117 mounted nonerotatably thereon.Mounted on the shafts 116 above the bracket 72 is an actuating Vknob 118for rotating the shaft 116 and the pinion 117 whereby the rack andelongated member 109 are moved longitudinally `of the bracket 72. Tolock the elongated member 109 inselected positions relative to thebracket 72, l provide a vertical opening 119 in the bracket 72 forreceiving ya threaded pin 121 having an operating knob 122 adjacent theupperend thereof. r[he lower end of the threaded pin 121 is adapted toengage the upper surface of the rack 113 lwhereby the rack and elongatedY member are locked inselected positions.

Mounted adjacent the outer end or the arm or elongated member 109 is adepending bracket 123 which is secured to the elongated member bysuitable screws 124. Mounted adjacent the upper and lower ends of thebracket 123 and at one side thereof are upper and lower brackets 126 and127, respectively, having suitable openings therethrough for receiving acylindrical Vmember 128, as shown in Fig. 7. The cylindrical member 128is held in selected positions relative to the brackets 126 and 127 bymeans of set screws 129 and 131. The cylindrical member 128 is adaptedto receive a drawing or marking member, such as a pencil 132. Thedrawing member 132 is held in selected positions relative to .thecylindrical member 128 by upper and lower collars 133 and 134,respectively. The collars 133 and 134 are attached to the pencil 132 bymeansof set screws 136 and 137. Positioned between the collars 1 33 and134 and the adjacent ends of Athe cylindrical member 128 are compressionsprings 138 and 139, respectively, Vwhich resiliently holdV the pencilin place whereby it is adapted for vertical movement upon Y theapplication of a predetermined pressure to the point of the pencil.

Pivotally mounted -to -the bracket 123 by means of a pivot pin 141 is anoutwardly extending bracket 142. As shown in Fig. 7, -the -bracket 142comprises laterally spaced arms 143 and 144. VVMounted between the outerends of the arms 143 and 144 is a block member 146 which is secured tothe outer ends of the arms 143 and 144 by screws 147 and 148. The blockmember 146 is provided with `a centrally disposed opening therethroughThe collars 153 and 154are locked to the pencil by means of set screws156 and 157, respectively. Positioned between the collars 153 and 154and the adjacent ends of the 'cylindrical member 149 are compressionsprings and 159 which resiliently hold the pencil 152 in place. YAlongitudinally extending groove 161 is provided in the upper surface ofthe elongated member 109, as shown in Fig. 2 for slidably receiving anelongated rack member 162. Mounted on top of the bracket 72 is anoutstanding bracket 163 which is secured to the bracket 72 by screws164. Mounted for rotation adjacent the outer end of the bracket 163 on atransverse shaft 166 is a gear 167 which is disposed to engage the rack162 whereby the rack is moved longitudinally of the groove 161. Theshaft 166 is rotated by means of an actuating knob 165. Secured to theouter end of the rack 162 is a threaded member 168 which extends througha suitable opening 169 provided in the depending bracket 123, as shownin Fig. 2. An adjusting nut 171 is mounted on the threaded member 168outwardly of the depending bracket 123 whereby inward movement of thethreaded member relative to the bracket 123 is limited. Secured rigidlyto the outer end of the threaded member 168 is a U-shaped bracket 172which is adapted to engage the upper portion of the cylindrical member149 whereby it is moved about the pivot pin 141, as shown in dottedlines in Fig. 1. Positioned between the lower end of the dependingbracket 123 and the lower end of the cylindrical member 149 is acompression spring 173 which urges the lower end of the cylindricalmember 149 outwardly whereby the pencil 152 returns to the solid lineposition upon release of the actuating knob 165 which rotates the shaft166 and gear 167. It should be noted that pencil 152 is out ofengagement with the supporting surface while pencil 132 is making acircular mark. Upon actuation of knob 165, pencil 152 engages thesupporting surface and makes a mark across the circular mark or linemade by pencil 132.

As shown in Fig. 6, the side of the elongated member 109 opposite therack 113 is provided with a suitable scale 174 to indicate the positionof the marking members relative to the center of the apparatus. Asuitable window 176 is provided in the plate 111 whereby the scale 174is exposed. The window 176 is provided with a vertical index member 177to indicate the exact position of the scale 174.

Mounted in the base beneath the plate 17 is a suitable magnet 178 forholding the apparatus in predetermined alignment with a supportingmagnetizable surface, such as the surface in which bolt holes or thelike are to be indicated.

From the foregoing description, the operation of my improved layoutinstrument will be readily understood. The base 10 is attached to thesupporting surface by means of the magnet 178 whereby it is held inpredetermined alignment with the supporting surface. That is, the base10 is aligned whereby the index mark 177 lies at the center of theangularly spaced marks to be laid out or indicated. With the base 10locked in this position by the magnet 173, the arm 74 is moved byadjusting the actuating member 79 so that the latch 8S overlies theselected annular member 37, 38, 39, 41 or 42, as the case may be. Thatis to say, if it is desired to indicate marks 45 apart, the latch 8S ismoved whereby it overlies the annular member 37. Upon rotation of theelongated member together with the bracket 72, the reduced portion 89 ofthe latch S8 falls into the adjacent recess 49. rhe elongated member 109is adjusted to the proper radius by rotating the actuating knob 118thereby turning the gear 117 to move the rack 113 and the elongatedmember relative to the bracket 72. 'Ihe elongated member 109 is thenlocked in place by the operating knob 122. With the elongated member setin the proper position, as indicated by the position of the scale 174relative to the index member 177, the actuating knob 165 is turned so asto urge the rack 162 outwardly thereby moving the U-shaped bracket 172,the marking member 152 and the bracket 142 about the pivot pin 141 tothe dotted line position shown in Fig. 1. Upon release of the actuatingknob 165, the spring 173 returns the marking member 152 to its originalposition. The latch 88 is then lifted by moving the handle portion 103of the lever arm 99 downwardly. The elongated member 109 and bracket 72are then rotated until the latch 88 falls into the next recess which ispositioned an angular distance or" 45. This procedure is repeated untilthe desired number of marks 45 apart are indicated on the member beinglaid out.

To space the marks 15 apart, the arm 74 is adjusted by turning the knob79 until the latch 8S is over the annular member 38. If it is desired toposition the marks 30 apart, the arm 74 is moved whereby the latch 88 ispositioned over the annular member 39.

To position the marks 2 apart, the arm 74 is adjusted whereby the latch88 is positioned over the annular member 41 or 42. If it is desired toposition the marks 1 apart, the marks are rst made by positioning theactuating rod 88 over the annular member 41 whereupon the marks are made2 apart. The arm 74 is then moved outwardly whereby the latch 88 ispositioned over the annular member 42. The marks are then applied midwaybetween the 2 marks made while the latch was over the annular member 41.It will thus .be seen that by varying the position of the arm 74 and thelatch 88 carried thereby, a plurality of pre-determined angularly spacedmarks may be applied to the surface to be laid out. To provide furtheradjustment of the device, the entire plate 31 carrying the annularmembers 37, 33, 39, 41 and 42 may be rotated by turning the actuatingknob 26 to position the detent 63 in selected ones of the recesses 64,65, 66 and 67.

It will thus be seen that as the elongated member 109 is rotated, themarking member 132 makes a circular path as determined by the positionof the elongated member 109 relative to the index mark 177. By adjustingthe position of the arm 74 whereby the latch S3 is positioned over thedesired annular member, the elongated member rotates a predeterminedangular position until the latch 88 falls into the next recess whereuponthe knob 165 is turned to actuate the gear 167 to cause movement of themarking member 152 about the pivot pin 141 thus making a marktransversely of the circular mark made by the marking member 132. Byproviding the angularly spaced recesses in the annular members togetherwith the releasable latch 88, the angularly spaced marks may beaccurately indicated sequentially on the member to be laid out in aminimum of time.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modiiications .without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are specifically set forth in the appended claims.

What I claim is:

l. A layout instrument comprising a supporting base, magnetic meansholding said base in predetermined alignment with a supporting surface,a plurality of concentric annular members mounted on said base andadapted to lie substantially parallel to said supporting surface, therebeing a plurality of angularly spaced recesses in each of said annularmembers, a rotatable bracket mounted for rotation on said base adjacentthe center of said annular members, an elongated member mounted on saidbracket and adapted for longitudinal adjustment relative to saidbracket, an arm carried by said bracket and extending outwardlysubstantially parallel to said annular members on the sides thereofadjacent said recesses, means for moving said arm radially of saidannular members, a. latch mounted adjacent the outer end of said armadapted to be disposed over a selected one of the annular membersthrough radial adjustment of said arm, spring means urging said latchinto engagement with the recesses in the selected annular member, meansfor removing said latch from said recesses, a marking member mountedadjacent the outer end of said elongated member and adapted to make acircular mark in response to circular movement of said outer end of theelongated member, a second 7 markingrmember mounted adjacent the outerend of said elongated member and being oiset angularly from said firstmarking member, and means moving said' second marking member relative tosaid iirst mentioned marking member and transversely of the mark made bythe viir'st mentioned marking member;

2. A layout instrument comprising ay supporting base,

magnetic means holding said base in predetermined align-V ment with asupporting surface, a plurality of concentric annular members mounted onsaid base and adapted to lie substantially parallel to said supportingsurface, there being a plurality of angularly spaced recesses in each ofsaid annular members, a rotatable bracket mounted for rotation on saidbase adjacent the center of said annular members, an elongated membermounted on-said bracket and adapted for longitudinal movement relativethereto, an elongated rack extending alongside and carried by saidelongated member, a pinion carried by said bracket in position toVengage said rack, means rotating said pinion whereby the position of theelongated member is adjusted relative t said bracket, an arm carried bysaid bracket and extending outwardly substantially parallel to saidannular members on the sides thereof adjacent said recesses, means formoving said arm radially vof said annular members a latch mountedadjacent the outer end of said arm adapted to be disposed over aselected one of the annular members through radial adjustment of saidarm, means urging said latch into engagement withV the recesses in theselected annular member, means for removing said latch from saidrecesses, a marking member adjacent the outer end of said elongatedmembery and adapted to make a circular mark in response to circularmovement of said outer end of the elongated member, a second markingmember mounted adjacent the outer end of said elongated member, saidsecond marking member being oiset angularly from said first markingmember and being positioned at substantially the same distance from `theaxis of rotation of Said elongated member as said first marking member,and means moving said second marking member relative to said rstmentioned marking member and transversely of the mark made by the iirstmentioned marking member.

3. A layout instrument comprising a supporting base, magnetic meansholding said Vbase in predetermined alignment with a supporting surface,an annular member mounted on said 4base and adapted to lie substantiallyparallel to said supporting surface, there being a plurality ofangularly spaced recesses in said annular member, a bracket mounted forrotation on said base adjacent the center of said annular member,vr anelongated member carried by said bracket and adapted for longitudinaladjustment relative thereto, a latchY carriedY by said bracket andadapted to engage the recesses in said annular member, means forremoving said latch from said recesses, ra marking member mountedadjacent the outer end of said elongated member and adapted to make acircular markrin response to circular movement of the outer end of theelongated member, a second marking member mounted for pivotal movementintermediate its ends adjacent the outer end of said elongated member,said second marking member being olset angularly from said iirst markingmember and being Vpositioned at substantially the same distance from theaxis of rotation of said elongated member as said first marking member,and an actuating member carried by said elongated member disposed toengage and pivot said second marking member relative to the rstmentioned marking member and said elongated member in a plane parallelto the longitudinal axis of the elongated member whereby the secondmarking member makesra mark transversely of the mark made by the nrstmen-Y tioned marking member.

4. A layoutinstrument as dened-inlclaim 3 inw`hichl the actuating membercomprises van; elongated rack mounted for sliding movement relative tothe elongated` member, a pinion carried by the bracket and disposed toengage said rack, means for rotating said pinion and means at the outerend of said rack disposed to engage said second marking member.VV

- 5. A layout instrument as dened in claim 4- in which a substantiallyU-shaped bracket is mounted at the outer en'd ofthe rack for engagingthe second marking member at one side of its pivotal connection to theelongated member.

6. A layout instrument as dened in claim 5 in Which a depending bracketis mounted adjacent the outer end of the elongated member and the secondmarking member is pivotally connected intermediate its ends to saiddepending bracket with the U-shapedv bracket positioned at one side ofthe pivoted connection and spring means interposed between the secondmarking member and said depending bracket on the opposite side of saidpivotal connection from said U-shaped bracket.

7. A layout instrument comprising a supporting base, magnetic meansholding said base in predetermined alignment with a supporting surface,an annular member mounted on said base and adapted to lie substantiallyparallel to said supporting surface, there being a plurality ofangularly spaced recesses' in said annular member, a bracket mounted forrotation on said base adjacent the center of said annular member, anelongated member carried by said bracket and adapted for longitudinaladjustment relative thereto, means locking said elongated member atselected positions relative to said bracket, a latch carried by saidbracket and adapted to engage the recesses in said annular member, meansfor removing said latch from said recesses, a marking member Vmountedadjacent the outer end of said elongated member and adapted to make acircular mark in response to circular movement of'the outer end of theelongated member, a second marking member mounted adjacent the outer endof said elongated member, said second marking member being oifsetangularly from said first marking member and being positioned atsubstantially the same distance from the axis of rotation of saidelongated member as said first marking member, and means on saidelongated member moving said second marking member relative to said irstmentioned marking member and transversely of the mark made by the iirstmentioned markingmember.

8. A layout instrument as defined in claim 7 in which the markingmembers are in the form of cylindrical members for receiving pencils,the first mentioned marking member being mounted rigidly on theelongated member and the second marking member being pivotally mountedon the elongated member.

9. `A layout instrument comprising a supporting base,

means holding said base in predeterminedralignment with a supportingsurface, an annular member mounted on said base and adapted to liesubstantially parallel to said supporting surface, there being aplurality of angularly spaced recesses in said annular member, anelongated member mounted for rotary movement intermediate its ends onsaid base and adjacent the center of said annular member, meansadjusting said elongated member longitudinally of said base, ,a latchrotatable with said elongated member and adapted toY engage the recessesinl said annular member, means for releasing said latch from Vsaidrecesses, a tubular member mounted adjacent the outer end of saidelongated member and extending substantially normal thereto, a markingmember mounted for axial movement Withinsaid tubular member and adaptedto make a circular mark in response to circular movement of said outerend of the elongated member, a second tubular member pivotally mountedintermediate its ends adjacent the outer end of said elongated memberand transversely thereof, said second tubular member extendingsubstantially parallel to therst mentioned tubular member, a secondmarking member mounted for axial movement within said second tubularmember, said second marking member being offset angularly from saidfirst marking member and being positioned at substantially the samedistance from the axis of rotation of said elongated member as said rstmarking member, means moving said second tubular member about its pivotpoint relative to said rst mentioned marking member whereby the secondmarking member moves transversely of the mark made by the firstmentioned marking member, spring abutments adjustably connected to saidmarking members in spaced relation to the ends of said tubular members,and compression springs surrounding said marking members intermediatesaid spring abutments and the ends of said tubular members.

10. A layout instrument comprising a base, means holding said base inpredetermined alignment with a supporting surface, at least one annularmember mounted on said base and adapted to lie substantially parallel tosaid supporting surface, there being a plurality of angularly spacedrecesses in said annular member, a bracket mounted for rotation on saidbase adjacent the center of said annular member, an elongated memberextending transversely of said bracket and adapted for longitudinaladjustment relative thereto, means carried by said bracket and adaptedto engage selectively the recesses in said annular member, a firstmarking member mounted adjacent the outer end of said elongated memberand adapted to make a circular mark in response to circular movement ofthe outer end of the elongated member, a second marking member pivotallymounted adjacent the outer end of said elongated member at substantiallythe same distance from the axis of rotation of said elongated member assaid first marking member and being offset angularly from said firstmarking member, and means on said elongated member to pivot said secondmarking member in a plane generally parallel l@ to the longitudinal axisof said elongated member and across the circular mark made by said rstmarking member whereby a cross mark is made for positioning bolt holesand the like.

11. An instrument for drawing and marking layout circles comprising asupporting base, means holding the base in predetermined alignment witha supporting surface, a bracket mounted for rotation on said base, anelongated arm carried by said bracket and extending therefrom over thesurface on which the circle is to be drawn, means mounting said arm forlongitudinal adjustment to selected positions relative to the center ofrotation of said bracket, a drawing member mounted adjacent the outerend lof said arm and adapted to draw a circular line on said surface inresponse to circular movement of the arm, a marking member mountedadjacent the outer end of said arm at substantially the same radialdistance from the axis of rotation of said arm as said drawing member,but on a diierent radius and angularly displaced from said drawingmember, said marking member being out of contact with said surface whilethe circular line is being made by said drawing member, and means onsaid arm to move said marking member radially of the circular line andinto contact with the surface to make a mark across the circular linemade by said drawing member.

References Cited in the le of this patent UNTED STATES PATENTS D.102,387 Moses Dec. l5, 1936 342,464 Richards May 25, 1886 352,693 IrvingNov. 16, 1886 416,097 Dyar Nov. 26, 1889 435,244 Ourdan Aug. 26, 18902,551,747 Ille Nov. 22, 1949 2,607,990 Payamps Aug. 26, 1952 2,735,190Jordan et al. Feb. 21, 1956

